Railroad car retarder

ABSTRACT

A railroad car retarder having pivoted levers for presenting retarding elements to a car wheel has the levers normally biased to a wheel engaging position by a coil spring. The levers may be actuated to a released position by a fluid-operated cylinder, compressing the spring. Means are interposed between the cylinder and adjacent lever in order to relieve the cylinder of shock when the retarder is restored, as by a car moving in or out of the retarder.

United States Patent Inventor Appl. No.

Filed Patented Assignee Earl E. Frank Tallman, N.Y. 39,448

May 21, 1970 Nov. 23, 1971 Abex Corporation New York, N .Y.

RAILROAD CAR RETARDER 3 Claims, 4 Drawing Figs.

US. Cl

Int. Cl. Field of Search [88/62, 188/170 B6lk 7/02 188/32, 62, 170

[56] References Cited UNlTED STATES PATENTS 2,104,186 1/1938 Clausen 188/62 2,630,884 3/1953 Bone 188/62 Primary E.raminerDuane A. Reger Attorney-Kinzer, Dorn and Zickert ABSTRACT: A railroad car retarder having pivoted levers for presenting retarding elements to a car wheel has the levers normally biased to a wheel engaging position by a coil spring. The levers may be actuated to a released position by a fluidoperated cylinder, compressing the spring. Means are interposed between the cylinder and adjacent lever in order to relieve the cylinder of shock when the retarder is restored, as by a car moving in or out of the retarder.

PATENTEnunv 23 I9" SHEET 2 [IF 2 RAILROAD CAR RETARDER This invention relates to railroad car retarders in which the retarder levers are biased to a closed position by a strong coil spring, the levers being spread when a car wheel enters therebetween.

Railroad car retarders of the foregoing kind, installed in a railroad classification yard, apply a retarding force due to the tendency of the spring to close the retarder elements against the opposed sides of the car wheel. Thus when the car wheel leaves the retarder, the retarder elements move to their closed position by the action of the spring.

It is desirable and advantageous to be able to open the retarder elements on demand, as for instance when the vehicle has been slowed sufficiently, or when it may be necessary to trail a car through the retarder without relying upon the action of the retarder. This can and has been done by hydraulic means, that is, by associating the retarder with a hydraulic system whereby piston or ram action may be relied upon, through appropriate connections. to pivot the levers to their open or released position.

Experience shows, however, that the hydraulic system can undergo a great deal of damage when the retarder restores to its normal state, by its own action, as when a car wheel enters the retarder, and the primary object of the present invention is to prevent damage to the hydraulic system and relieve or bias retardation forces applied to the car wheel as desired. A related object is to isolate the hydraulic system in such a way that the forces established upon restoration of a spring-biased retarder are absorbed or isolated. Another object of the present invention is to enable a car retarder to be released or opened by hydraulic forces while so modifying the arrangement as to take the shock of restoration off the hydraulic equipment.

While I refer to hydraulics, the principle of the invention is equally applicable to air as another source of fluid under pressure.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawing which, by way of illustration, shows a preferred embodiment of the present invention and the principle thereof and what is now considered to be the best mode contemplated for applying that principle. Other embodiments of the invention embodying the same or equivalent principles maybe made as desired by those skilled in the art without departing from the present invention.

In the drawings:

FIG. 1 is an elevation of a car retarder constructed in accordance with the present invention, showing some parts in section, the retarder being in its normal or closed state;

FIG. 2 is a view similar to FIG. 1 but showing the retarder in its open or released state;

F IG. 3 is a detail sectional view of the cylinder; and

FIG. 4 is a fragmentary view illustrating what could happen contra the present disclosure.

The retarder system of the present invention, FIG. 1, includes a pair of levers l and 12 pivotally mounted on support shafts 11 and 13, the shafts l1 and 13 being located on opposite sides of the traffic rail T. The shafts l1 and 13 are supported by respective brackets 15 and 16 secured to the web or plate of the traffic rail as by bolts 20.

The levers and 12 include upper portions presenting retarder elements 21 engageable with the opposite sides of a car wheel moving along the traffic rail T. The retarder elements 21, in the idle or at-rest state, are normally separated by a distance less than the width of a car wheel, being biased to this normal or closed position, shown in FlG. l, by a large coil spring 23 having the opposite ends thereof bearing on the opposed inner faces of the lower extremities of the levers l0 and 12.

A guide rod 24 extends through appropriately sized openings in the lower ends of the lever arms 10 and 12, being coaxial with the spring 23. One end 24A of the rod extends outward of the left-hand lever 10, and a nut 25 is mounted thereon together with a washer 26 serving as a stop to limit the normal position of the left-hand lever 10 under the biasing influence of the spring 23. The right-hand lever 12, in principle, is limited in a similar fashion in a manner now to be described.

The rod 24 extends outward to the right beyond lever 12, through an aperture in a washer 27, through the chamber of a grease cup 28, through a cylinder 29, and finally the extreme right-hand end 24B of the rod 24 terminates in a threaded portion on which is mounted a nut 32 and a washer assembly 33. Thus the nut 32, like the nut 26, is a fixed stop on one end of the rod 24 limiting the normal position of the right-hand lever 12 under the biasing influence of the spring 23.

The purposes and functions of the washer 27, the cup 28 and the cylinder 29 will be described in more detail below, but it may be explained at this phase of the disclosure that when a car wheel on the traffic rail T moves into the space between the retarder elements 21, the latter are spread outward away from one another to allow entry of the car wheel. Such spreading action of the car retarder elements 21 is manifest in their pivotal movement about the support shafts 11 and 13 whereby the lower ends of the levers concurrently move inward toward one another on the guide rod 24, compressing the spring 23. As can be visualized in FlG. 1, lever 10 will pivot counterclockwise and lever 12 will pivot clockwise. The retarding force on the car wheel, due to the retarding elements engaging the opposite sides of the car wheel, is determined by the rate of spring 23. When the levers l0 and 12 are thus pivoted due to entry of a car wheel, the lower end portions of the levers l0 and 12 move inward toward one another, away from the washers 26 and 27.

The cylinder 29, FIG. 3, houses a piston 40, the piston 40 having a bore 41 therein through which rod 24 extends.

The piston 40 includes a collar 42 adapted to slide within a chamber 43 in the cylinder 29. Suitable seals (not numbered) are interposed in chamber 43 behind the rear face of the collar 42, sealing a chamber 43A.

The cylinder 29, FIG, 3, is provided with an opening 49 in which is anchored a fitting 50 supporting a nipple 51 adapted to be connected to a source of fluid under pressure, communicated to the cylinder chamber 43A behind collar 42 through a passage 52, F IG. 3. Thus when fluid under pressure is directed to the fitting 50, piston 40 is moved forwardly or to the left as viewed in FIG. 1, and eventually the forward end 40E thereof presses against the rear face of the grease cup 28, moving the latter, together with the washer 27, against the outer face of the lower end of lever 12. At the same time fluid under pressure in chamber 43A tends to move the cylinder 29 rearwardly or to the right, but the cylinder is stopped in this movement by the stop assembly 32-33. Resultantly rod 24 is pulled to the right, and the nut 25 thereon is effective to press forcefully the washer 26 against the outer face of the lefthand lever 10. Compressive forces are acting on both ends of the spring 23, which is thereupon compressed. The retarder is then in its fully released state, FIG. 2, allowing a car wheel to move freely out of or through the retarder.

When the supply of fluid under pressure to chamber 43A is interrupted, and allowed to vent or bleed, the compressive forces acting on spring 23 are released, whereupon the spring expands, tending to restore the parts characterizing the open position of the retarder shown in FIG. 1.

Thus it will be seen that the retarder may be easily opened, through a hydraulic system, to release a car wheel or indeed to allow a car wheel to move through the retarder entirely without any retarding action being exerted thereon. However the more important consideration concerns the circumstance where the retarder levers 10 and 12 have been spread apart by a car wheel, moving the lower ends of the levers away from the washers 26 and 27 and compressing the spring. Now, when the trailing wheel of a car leaves the retarder the compressed spring 23 exerts a sudden expansion or outward thrust which, if it were not for the interposition of an enlargement 55 on the piston 24, within the grease cup 28, would result in the lower end of the right-hand lever 12 hammering directly on the ram 40. This can be appreciated from FIG. 4, where it is assumed that the piston 40 is in position to bear directly on lever 12.

3 Viewed another way if the end 40E of the piston 40 should be in position to bear directly on the outer face of the lower end of lever 12 (with or without the washer 27). and if the levers were then pivoted by a car wheel to compress the spring, release of the spring after the wheel leaves would cause the outer face of the lower end of the right-hand lever 12 to hammer on the adjacent end 40E of the piston, FIG. 4, but under the present invention the brunt of this thrust is absorbed by the enlargement 55 on the rod 24, FIG. I. The washer 27 is used only as a centering aid, which is to say that it can be omitted with the parts reconstructed to have the shoulder 55 bearing on the rounded face 12R at the lower end of lever 12.

It will be seen from the foregoing that under the present invention the levers of a railroad car retarder, having upper portions engageable with opposed sides of the car wheel, have lower portions between which a compression spring is disposed, mounted on a guide rod extended through apertures in the lower ends of the retarder levers. The spring serves to establish the retarding force in that the levers are spread at their upper ends against the return action of the spring when a car wheel enters the retarder. One end of the guide rod is outward of one of the levers (e.g., lever and a stop is provided thereon to limit the position of the adjacent lever. The rod extends for a considerable length outward of the other lever, and a cylinder is mounted on this extended portion ofthe rod, with one end of the cylinder adapted to bear against a second stop on the rod, at the end opposite the first-named stop. The cylinder houses a ram operable by fluid under pressure, the piston moving outward of the cylinder in the direction of the lower end of the adjacent retarder lever (lever 12) and in doing so the cylinder slides on the rod, the rod being coaxial therewith. Spacer means (e.g., the grease cup 28 and washer 27) is interposed between the operable end of the cylinder and the adjacent lever, and is effective to transfer the force of the cylinder to the adjacent lever, whereby eventually the levers are pivoted to their open or released position.

The s acer preferably includes a grease cup in which is housed an enlarged shoulder on the rod, and it is this shoulder which actually absorbs the force of the spring when the retarder is restored, as by its own action as a car wheel moves out of the retarder.

Of course the parts may be reversed. For example, the cylinder may be turned so that its rear or closed end bears against the spacer means 28, with the end 40E of the piston acting against the stop washer 33. Other changes, equivalent in principle and means, may be made.

Hence while I have illustrated and described a preferred embodiment of my invention it is to be understood that this is capable of variation and modification.

lclaim:

1. In a railroad car retarder characterized by a pair of levers pivotally mounted on opposite sides of a traffic rail, the levers having upper end portions each supporting a retarder element engageable with a car wheel and having lower end portions en gaged with and separated by a spring which is effective to bias the levers to a normal position where the retarder elements are separated by less than the width of a car wheel: a guide rod extended through the lower portions of the levers and extending outward of each lever, one end of the rod having a stop thereon engaging the adjacent lever to limit the normal position thereof, a cylinder for receiving fluid under pressure mounted on the rod outward of the other lever, said cylinder having a piston therein extendable outward of one end thereof, the rod having a second stop on its other end disposed opposite one end of the cylinder, spacer means on the rod between the cylinder and the other lever whereby fluid under pressure admitted to the cylinder is effective to compress the spring and spread the retarder elements to a wheel releasing position, and a shoulder on the rod between the cylinder and the adjacent lever to absorb the shock of retarder restoration.

2. A retarder according to claim 1 where the spacer means includes a grease cup housing said shoulder on the rod.

3. A retarder according to claim 2 wherein a ram bears on the spacer and wherein the end of the cylinder opposite the ram bears on the second stop.

* k I I 

1. In a railroad car retarder characterized by a pair of levers pivotally mounted on opposite sides of a traffic rail, the levers having upper end portions each supporting a retarder element engageable with a car wheel and having lower end portions engaged with and separated by a spring which is effective to bias the levers to a normal position where the retarder elements are separated by less than the width of a car wheel: a guide rod extended through the lower portions of the levers and extending outward of each lever, one end of the rod having a stop thereon engaging the adjacent lever to limit the normal position thereof, a cylinder for receiving fluid under pressure mounted on the rod outward of the other lever, said cylinder having a piston therein extendable outward of one end thereof, the rod having a second stop on its other end disposed opposite one end of the cylinder, spacer means on the rod between the cylinder and the other lever whereby fluid under pressure admitted to the cylinder is effective to compress the spring and spread the retarder elements to a wheel releasing position, and a shoulder on the rod between the cylinder and the adjacent lever to absorb the shock of retarder restoration.
 2. A retarder according to claim 1 where the spacer means includes a grease cup housing said shoulder on the rod.
 3. A retarder according to claim 2 wherein a ram bears on the spacer and wherein the end of the cylinder opposite the ram bears on the second stop. 